The attack, which was carried out on June 19, is the latest in a string of military operations in Pakistan's tribal regions. The government launched a massive anti-Taliban operation in nearby South Waziristan last October.

Local sources, however, confirmed the death of only four Taliban in the air strike. Noor Muhammad, an influential local resident in the Mohmand agency, told Radio Mashaal on June 21 about the attack and reports of civilian casualties.

"This happened in an area bordering Afghanistan called Khwezai-Baizai. The Taliban have hideouts there," Muhammad said. "Pakistani gunship helicopters bombed that area, resulting in the killing of four militants and injury of 10. It is also said that one woman was killed and a child was injured in the attack."

Locals believe the militants are now entering Mohmand following the Pakistani Army operations in Waziristan and the nearby Orakzai tribal agency.

Local resident and NGO employee Shah Nawaz Khan told Radio Mashaal that the Taliban had been driven out of the lower parts of Mohmand with the help of a local army of tribal volunteers. However, he said they still retained control of upper Mohmand, a mostly mountainous and inaccessible area.

"The [Taliban] -- we can say that they are present there, because each week one or two leaders of [the army of tribal volunteers] are killed by unidentified people in those areas," Khan said.

Hundreds of families were uprooted from their houses following an operation by the Pakistani security forces in the Mohmand agency in late 2008. The military had used heavy artillery, helicopters, and jet fighters.

Though the government declared the area a Taliban-free zone and asked the displaced people to return home, locals continued to doubt the assurances of security.

Peshawar-based analyst Mushtaq Yousufzai told Radio Mashaal on June 21 that the government had not succeeded in the area during its earlier operations.

"I can say that the situation did not improve as much as claimed by the government," Yousufzai said. "Just look at the government claim it had killed Taliban leaders Omar Khalid, commander of the Swat Taliban Fateh, and Qari Ziaur Rehman, an Afghan and important commander of Bajaur Taliban. It is said they are alive and were not killed in the operations."

The air strike and other recent attacks on Pakistani security forces illustrate increasing troubles in Mohmand.

Last week, Taliban insurgents attacked a security post of Pakistan's semi-military Frontier Corps in Mohmand, killing six soldiers and kidnapping several others. The bodies of six more soldiers, believed to have been killed by the militants in captivity, were handed over to tribal elders by the militants.